1. Field of the Invention
At least one embodiment of the invention generally relates to implantable medical devices that may later be detached and which may include electrodes, including electrode leads and leadless medical implants having at least one electrode and more particularly, but not by way of limitation, embodiments of the invention relate to a detachable electrode and anchor that may be detachably released from one another to explant the electrode and associated lead or leadless implant.
2. Description of the Related Art
Electrodes in the form of electrode leads or leadless medical implants are commonly implanted in patients in need of cardiac monitoring and if necessary, electrical stimulation. Electrical energy is sensed over the electrodes and analyzed, generally with an associated implantable medical device, or external device. Therapeutic energy is provided to the electrodes implanted in a heart for example to ensure that the heart provides life-sustaining contractions that pump blood through the patient's body. Generally, electrodes are physically attached to the heart in a manner that is intended to be relatively permanent, so as to ensure long term robust electrical contact with the specific heart tissue that the electrode is attached to. Typical electrodes provide attachment mechanisms such as screws or tines that project in one way or another into the tissue of the heart. Leadless devices have many advantages includes avoiding problems associated with lead failure.
When an electrode lead is no longer needed, or becomes inoperable, or otherwise is to be replaced, the electrode lead may be left in place, or removed. Leaving unused electrode leads in place is suboptimal in that the unused leads may interfere with the internal workings of the veins or portion of the heart in which they remain. Alternatively, removing the electrode lead may damage the tissue where the electrode lead is attached. If the electrode lead is to be removed, one such method of removing an unwanted electrode lead requires use of an additional sheath that is placed over the electrode lead that abuts against the heart tissue where the electrode lead is attached. The electrode lead is then physically removed from the scar tissue that has grown around the attachment portion or anchor of the electrode lead, for example the tines. Optionally, a laser or mechanical drill may be utilized to cut or otherwise remove scar tissue surrounding the tines before the anchor of the electrode lead is removed. The main problem with this technique is that the extraction site is subject to internal bleeding. Leadless medical implants on the other hand are generally never removed and remain attached to tissue even after a battery within the device is drained, which is also suboptimal.